10. Sweaters are used (keep) warm.

9. It is a long time since the house (build) .

8. It is impolite to say nothing when you (ask) to answer the teacher’s question.

7. — What’s your plan for the coming holiday?

   —I (visit) Beijing if possible.

6. The doctors (operate) on the girl when we got to the hospital.

5. The government (change) the areas around the Tai lake into a beautiful park.

4. He was late because his car (break) down on his way to work.

3. Bad weather (cause) serious problems from time to time.

2. The day we were looking forward to (come) at last.

五、动词填空。(10分)

1. It’s a rule that magazines mustn’t (take) out of the reading room.